1. Field of the Invention
The present invention relates to a process cartridge and a process cartridge identification mechanism for image formation that is mounted in image forming apparatuses such as a laser printer, a facsimile machine, and a copier, as well as to an identification mechanism for such a process cartridge.
2. Description of the Related Art
Among image forming apparatuses are ones in which a process cartridge unit formed by accommodating a photoreceptor drum, a developer, etc. in a housing is provided in a detachable manner to improve the ease of maintenance and provide better service.
The specifications of internal functional components and a toner may vary among process cartridges due to various differences in the specifications of apparatus main bodies where the process cartridges are used, whereas external components such as a housing are common to the process cartridges. In this case, if a process cartridge is not compatible with an apparatus main body, a failure in image quality or malfunctioning of the apparatus may occur. To prevent such an event, it is necessary to employ a mechanism for prohibiting the use of such a process cartridge.
However, a conventional identification mechanism as disclosed in Japanese Unexamined Patent Publication No. Hei. 7-152307, for example, which electrically detects a process cartridge type, is not so configured as to identify many process cartridge types.
Japanese Unexamined Patent Publication No. Hei. 9-185311 discloses an identification mechanism in which the logo mark of a process cartridge is recognized by means of a switch. However, this identification mechanism has a problem that a process cartridge cannot be identified unless it is mounted correctly because the structure of the mechanism does not allow a large projection/recess amount of a logo mark nor a long stroke of the switch.
Further, it is necessary to provide, in addition to such an identification mechanism, the following components in the mounting section. That is, as shown in FIG. 15, it is necessary to provide not only a detection switch 88 for detecting whether a process cartridge is mounted and an interlock switch for turning off the apparatus when a process cartridge is removed or a main body cover is opened, but also a power switch 90 for turning off the power of a laser diode to secure the safety.
In view of the above, for example, a configuration is possible in which seven projection plates 92 are provided on the process cartridge 10 side and eight engagement portions 96 are provided at such positions as to be able to engage the projection plates 92 by elongating an actuator portion 94 on the mounting section side in the horizontal direction. A manipulation lever 98 for manipulating the detection switch 88 and the power switch 90 is selectively provided in the engagement portions 96 and is pushed down by the corresponding one of the projection plates 92. This configuration enables seven combinations of an image forming apparatus and a process cartridge. However, since the actuator portion 94 occupies a large space in the horizontal direction, this configuration is not efficient in terms of space utilization.
It is also possible to provide a maximum of 16 combinations by using an electrical logic circuit having 4-bit switches. However, a large-size assembly is needed to incorporate, to secure the safety, switches having a capacity large enough to turn off the power of a laser diode. It is noted that it is possible to replace the power switch 90 for turning off the power of the laser diode with another means.